Moving to Delaware as a master plumber: every state's rule

Delaware issues a person-held Master Plumber license through the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners in the Division of Professional Regulation. 24 Del. C. § 1807 requires that license (or a statutory exemption) to provide plumbing services or to use the titles licensed plumber / master plumber. Employees, apprentices and journeymen work under a master's supervision without their own Board license. A new master needs a journeyman's certificate from a federally-standard apprenticeship plus two years under a master plumber (or similar-level licensee in another state), or seven years under such supervision plus the Delaware vocational-technical apprenticeship equivalency tests, then Board approval and the ProV-administered master plumber exam; the application fee is $173. Out-of-state masters apply by reciprocity under 24 Del. C. § 1810 without a Delaware exam: the Board shall grant the license if the origin state's standards are substantially similar, and otherwise requires at least seven years of practice after licensure. 24 DE Admin. Code 1800 § 2.3 requires every reciprocity applicant to submit the origin state's licensure laws and regulations so the Board can make that comparison. Licenses renew biennially; from the 2026 renewal, plumbing licensees complete 5 hours of continuing education (3 code, 1 safety, 1 cross-connections/backflow) by October 31 of even-numbered years.